This studyUs objectives are to: (1) evaluate the safety and tolerability of single and multiple (10-day) dose oral administration of RS-25560 in patients with congestive heart failure (New York Heart Association Class II or III) and elevated plasma norepinephrine levels; (2) define the pharmacokinetic properties and pharmacodynamic effects of single and multiple oral doses of the compound in these patients; and (3) evaluate DBH inhibition with RS-25560 administration, as evidenced by a decrease in plasma norepinephrine levels and an increase in plasma dopamine levels in these patients.